Use of a polyamide chain-extending compound as a stabilizer

Abstract

The invention relates to the use of a polyamide chain-extending compound as an agent for stabilizing the polyamide toward heat, light and/or bad weather. Polyamide compositions may comprise at least one of these polyamide chain-extending compounds and optionally reinforcing fillers and optionally impact modifiers.

1 . A method for stabilizing the a polyamide composition toward heat, light and/or bad weather, comprising combining at least a polyamide and a polyamide chain extending agent to form the polyamide composition. 
     
     
         2 . The method of  claim 1 , the polyamide composition has a retention of the tensile breaking stress of greater than or equal to 50%, measured according to standard ISO 527/1A on specimens 4 mm thick after an aging test in air at 210° C. for 1000 hours, in comparison with the same composition before the aging test. 
     
     
         3 . The method of  claim 1 , wherein the polyamide chain-extending compound is chosen from the group consisting of: dialcohols, bis-epoxides, polymers bearing epoxide functions, polymers bearing anhydride functions, bis-N-acyl bis-caprolactams, diphenyl carbonates, bisoxazolines, oxazolinones, diisocyanates, organic phosphites, bis-ketenimines and dianhydrides. 
     
     
         4 . The method of  claims 1  wherein the polyamide composition comprises from 0.01% to 5% by weight of polyamide chain-extending compound relative to the total weight of the polyamide composition. 
     
     
         5 . The method of  claim 1  wherein the polyamide is chosen from the group comprising: polyamide 6, polyamide 610, polyamide 66, and polyamide 66/6T. 
     
     
         6 . The method of  claims 1  wherein the polyamide composition further comprises at least one reinforcing or bulking filler. 
     
     
         7 . The use method of  claims 1  wherein the polyamide composition further comprises at least one impact modifier. 
     
     
         8 . The use method of  claims 1  wherein the polyamide composition further comprises at least one other additive participating in the thermal stabilization of the composition. 
     
     
         9 . An article comprising a stabilized polyamide composition made by the method of  claim 1 , wherein the article is made for applications exposed to temperatures of greater than or equal to 80° C. 
     
     
         10 . The article as claimed in  claim 9 , wherein the article is manufactured to contain or transport fluids. 
     
     
         11 . A method for stabilizing a polyamide composition toward heat, light, and/or bad weather, comprising combining one or more polyamide chain extending agents that comprise at least a bisphenol A diglycidal ether chain extending agent with polyamide 66, an impact modifier, Cul, KI, and reinforcing glass fibers, to form the polyamide composition, wherein the stabilized polyamide composition exhibits a retention of the tensile breaking stress of greater than or equal to 50%, measured according to standard ISO 527/1A on specimens 4 mm thick after an aging test in air at 210° C. for 1000 hours, in comparison with the same composition before the aging test.